Aneurysm treatment with pushable implanted braid

ABSTRACT

The present invention provides a braided implant with a retractable dual proximal layer and methods for administering the braided implant to treat aneurysms. The implant can include a tubular braid that can be set into a predetermined shape, compressed for delivery through a microcatheter, and implanted in at least one implanted position that is based on the predetermined shape and the geometry of the aneurysm in which the braid is implanted. The implant can also have a retractable dual layer at the proximal end of the device made of the same braid to provide additional coverage at the neck of the aneurysm. The dual layer can be pressed distally into a first implanted portion of the tubular braid, moving the first portion of the tubular braid towards the distal portion of an aneurysm wall so that the implant can partially or completely occlude an aneurysm neck.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation-In-Part to U.S. application Ser. No.16/418,199 filed May 21, 2019, and this application in incorporatedherein in its entirety.

FIELD OF THE INVENTION

The present invention generally relates to medical instruments, and moreparticularly, to embolic implants for aneurysm therapy.

BACKGROUND

Aneurysms can be complicated and difficult to treat. For example,treatment access may be limited or unavailable when an aneurysm islocated proximate critical tissues. Such factors are of particularconcern with cranial aneurysms due to the brain tissue surroundingcranial vessels and the corresponding limited treatment access.

Prior solutions have included endovascular treatment access whereby aninternal volume of the aneurysm sac is removed or excluded from arterialblood pressure and flow. In this respect, because the interior walls ofthe aneurysm may continue being subjected to flow of blood and relatedpressure, aneurysm rupture remains possible.

Alternative to endovascular or other surgical approaches can includeocclusive devices. Such devices have typically incorporated multipleembolic coils that are delivered to the vasculature using microcatheterdelivery systems. For example, when treating cranial aneurysms, adelivery catheter with embolic coils is typically first inserted intonon-cranial vasculature through a femoral artery in the hip or groinarea. Thereafter, the catheter is guided to a location of interestwithin the cranium. The sac of the aneurysm can then be filled with theembolic material to create a thrombotic mass that protects the arterialwalls from blood flow and related pressure. However, such occlusivedevices do have certain shortcomings, including mass effect, which cancause compression on the brain and its nerves.

For example, embolic coils delivered to the neck of the aneurysm canpotentially have the adverse effect of impeding the flow of blood in theadjoining blood vessel, particularly if the entrance is overpacked.Conversely, if the entrance is insufficiently packed, blood flow canpersist into the aneurysm. Treating certain aneurysm morphology (e.g.wide neck, bifurcation, etc.) can require ancillary devices such astents or balloons to support the coil mass and obtain the desiredpacking density. Once implanted, the coils cannot easily be retracted orrepositioned. Furthermore, embolic coils do not always effectively treataneurysms as aneurysms treated with multiple coils often recanalize orcompact because of poor coiling, lack of coverage across the aneurysmneck, blood flow, or large aneurysm size.

Another particular type of occlusive approach endeavors to deliver andtreat the entrance or “neck” of the aneurysm. In such “neck” approaches,by minimizing blood flow across the neck, a cessation of flow into theaneurysm may be achieved. It is understood that the neck plane is animaginary surface where the inner most layer of the parent wall would bebut for the aneurysm. However, neck-occlusive approaches, such asimplanting a flow impeding device in the parent vessel, are not withoutdrawbacks. Such an approach may impede blood flow into peripheral bloodvessels while blocking the aneurysm neck in the parent vessel. Impedingflow to the peripheral blood vessel can unintentionally lead to severedamage if the openings of the vessels are blocked.

Alternatives to embolic coils are being explored, such as tubularbraided implants. Tubular braided implants have the potential to easily,accurately, and safely treat an aneurysm or other arterio-venousmalformation in a parent vessel without blocking flow into perforatorvessels communicating with the parent vessel. Compared to embolic coils,however, tubular braided implants are a newer technology, and there istherefore capacity for improved geometries, configurations, deliverysystems, etc. for the tubular braided implants. For instance, deliveryof tubular braided implants can require unique delivery systems toprevent the braid from inverting or abrading when pushed through amicrocatheter, and some simple delivery systems that push embolic coilsthrough microcatheters from their proximal end may not be effective todeliver tubular braids.

There is therefore a need for improved methods, devices, and systems forimplants for aneurysm treatment.

SUMMARY

It is an object of the present invention to provide systems, devices,and methods to meet the above-stated needs. Generally, it is an objectof the present invention to provide a braided implant with a retractabledual proximal layer. The implant can secure within an aneurysm sac andocclude at least a majority of the aneurysm's neck. The implant caninclude a tubular braid that can be set into a predetermined shape,compressed for delivery through a microcatheter, and implanted in atleast one implanted position that is based on the predetermined shapeand the geometry of the aneurysm in which the braid is implanted. Theimplant can also have a retractable dual layer at the proximal end ofthe device made of the same braid to provide additional coverage at theneck of the aneurysm.

In some examples presented herein, the dual layer can be shaped byexpanding it radially, and the dual layer can be pressed distally into afirst portion of the tubular braid already within the aneurysm. Bypressing the dual layer distally into the first portion of the tubularbraid, the first portion of the tubular braid can be moved towards thedistal portion of an aneurysm wall so that the implant can partially orcompletely occlude an aneurysm neck. Pushing the dual layer into thefirst portion of the braid can help conform the implant to the shape ofthe aneurysm and resist compaction. The dual layer when expandedradially and pressed into the first portion of the braid also canprovide additional coverage at the neck of the aneurysm to increasethrombosis. In some examples, the dual layer can also be placed withinthe aneurysm sac with only a detachment point external to the sac.

In some examples, the tubular braid can include memory shape materialthat can be heat set to a predetermined shape, can be deformed fordelivery through a catheter, and can self-expand to an implanted shapethat is based on the predetermined shape and confined by the anatomy ofthe aneurysm in which it is implanted.

In some examples the tubular braid can be shaped to a delivery shapethat is extended to a single layer of tubular braid having a compressedcircumference/diameter sized to be delivered through the microcatheter.

In some examples, before the implant is released from the deliverysystem, the implant can be partially or fully retracted into themicrocatheter and repositioned.

An example method for forming an occlusive device to treat an aneurysmcan include one or more of the following steps presented in noparticular order, and the method can include additional steps notincluded here. An implant with a tubular braid, an open end, and apinched end can be selected. The tubular braid can be shaped to apredetermined shape. Shaping the tubular braid to a predetermined shapecan also include further steps. These steps can include inverting thetubular braid to form a distal inversion. The tubular braid can also beinverted to form a proximal inversion by moving the open end over atleast a portion of the braid. A first segment of the tubular braidextending between the open end and the proximal inversion can be shaped.A second segment of the tubular braid extending between the proximalinversion and the distal inversion can be shaped. The open end can bepositioned to encircle the second segment. A third segment extendingfrom the distal inversion to the proximal inversion can be shaped. Thesecond segment can be positioned to surround the third segment. A fourthsegment of the tubular braid extending from the third segment radiallyoutward from a central axis to cross the proximal inversion can beshaped and can fold and converge at the pinched end. The fourth segmentcan be positioned near the neck of an aneurysm.

An example method for treating an aneurysm can include one or more ofthe following steps presented in no particular order, and the method caninclude additional steps not included here. A first portion of a tubularbraided implant, which can have a tubular braid, an open end, and apinched end, can be positioned within a sac of the aneurysm such thatthe first portion circumferentially apposes walls within the sac. Thefirst portion can have one or more inversions. A second portion of thetubular braided implant can be expanded radially to occlude a majorityof a neck of the aneurysm. The second portion can be pressed distallyinto the first portion. The first portion of the tubular braided implantcan be moved toward a distal portion of the aneurysm wall as a result ofpressing the second portion distally into the first portion.

In some examples, expanding the second portion of the tubular braidedimplant can include positioning a fold in the second segment to define asubstantially circular perimeter of the second portion and compressingthe second portion along a central axis of the tubular braided implantsuch that the second portion can have a substantially circular shapehaving an area and two layers of braid over a majority of the area ofthe substantially circular shape.

In some examples, positioning the first portion of the tubular braidedimplant can further include shaping the tubular braided implant to forma columnar post encircling a central axis of the tubular braided implantand extending a majority of a height of the first portion. In anotherexample, positioning the first portion of the tubular braided implantcan further involve positioning a proximal inversion near the neck ofthe aneurysm and positioning a distal inversion approximate the distalportion of the aneurysm wall. In another example, positioning the firstportion of the tubular braided implant can further involve positioningthe open end of the tubular braided implant to circumferentially apposethe aneurysm wall, shaping a first segment of the tubular braidextending between the open end and the proximal inversion to appose atleast a portion of a wall of the aneurysm within the aneurysm's sac, andshaping a second segment of the tubular braid such that the firstsegment provides an outwardly radial force in a plane defining aboundary between the aneurysm and blood vessel branches, the forcesufficient to appose the first segment to walls of the aneurysm.

In some examples, pressing the second portion distally into the firstportion can further involve pressing the second portion of the tubularbraided implant against the proximal inversion in the first portion ofthe tubular braided implant.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and further aspects of this invention are further discussedwith reference to the following description in conjunction with theaccompanying drawings, in which like numerals indicate like structuralelements and features in various figures. The drawings are notnecessarily to scale, emphasis instead being placed upon illustratingprinciples of the invention. The figures depict one or moreimplementations of the inventive devices, by way of example only, not byway of limitation.

FIG. 1A is an illustration of an example implant having a tubular braidin a predetermined shape according to aspects of the present invention;

FIG. 1B is an illustration of the example implant with the tubular braidin a first implanted shape according to aspects of the presentinvention;

FIGS. 2A through 2I are illustrations of an implant having a tubularbraid that expands to an implanted shape similar to as illustrated inFIG. 1B as the tubular braid exits a microcatheter according to aspectsof the present inventions;

FIGS. 3A through 3B are flow diagrams for a method of forming anocclusive device to treat an aneurysm; and

FIGS. 4A through 4B are flow diagrams for a method for treating ananeurysm.

DETAILED DESCRIPTION

Examples presented herein generally include a braided implant that cansecure within an aneurysm sac and occlude a majority of the aneurysm'sneck. The implant can include a tubular braid that can be set into apredetermined shape, compressed for delivery through a microcatheter,and implanted in at least one implanted position that is based on thepredetermined shape and the geometry of the aneurysm in which the braidis implanted. The implant can include a single layer of braid (e.g. abraid that can be extended to form a single layer tube) heat treatedinto multiple layers with retractable dual layer at the proximal end ofthe tubular braid. When compressed, the implant can be sufficientlyshort to mitigate friction forces produced when the implant is deliveredunsheathed through the microcatheter.

A first portion of the tubular braid can be positioned in an aneurysm,after which the retractable dual layer can be deployed from themicrocatheter and pushed onto the first portion of the tubular braid.This configuration provides three layers of braid at the neck of theaneurysm. The dual layer can potentially cover any gap between the firstportion of implanted tubular braid and the aneurysm neck, and canpotentially increase metal coverage, decrease porosity of the implant,and increase stasis and blood flow diversion at the neck of the aneurysmto promote the sealing and healing of the aneurysm compared a similarlyshaped braided implant lacking the dual layer. The entire implant can beretractable until a desired position is achieved.

FIGS. 1A and 1B are illustrations of an example braided implant 100 thatcan have a predetermined shape as shown in FIG. 1A and a distinctimplanted shape as illustrated in FIG. 1B. The implant 100 can treat arange of aneurysm sizes. The implant 100 can include a tubular braid 110having an open end 114 and a pinched end 112. The implant 100 caninclude a connection and detachment feature 150 (referred toequivalently as “connection feature” and “detachment feature” herein)attached to the braid 110 at the pinched end 112. The pinched end 112can include a marker band and/or soldered point with visibility, and/orthe connection feature 150 can include radiopaque material. The tubularbraid 110 can be formed in the predetermined shape (FIG. 1A), collapsedfor delivery through a microcatheter, attached to a delivery system atconnection feature 150, and implanted in an implanted shape such as theone shown in FIG. 1B.

Referring to FIG. 1A, when in the predetermined shape, the tubular braid110 can include two inversions 122, 124, a pinched end 112, and an openend 114. The tubular braid 110 can include four segments, 142, 144, 146,and 152. The first segment 142 can extend from the open end 114 of thetubular braid 110 to a proximal inversion 122. The second segment 144can be encircled by the open end 114 and extend from the proximalinversion 122 to a distal inversion 124. The third segment 146 can besurrounded by the second segment 144 and extend from the distalinversion 124 to the proximal inversion 122. The first segment 142,second segment 144, and third segment 146 can form the first portion ofthe tubular braid 110. The fourth segment 152 can extend from the thirdsegment 146 radially outward from a central axis to cross the proximalinversion 122, fold, and converge at the pinched end 112. The fourthsegment 152 can be partially encircled by the proximal inversion 122.

When in the predetermined shape, the tubular braid 110 can besubstantially radially symmetrical about a central vertical axis. Thedetachment feature 150 is illustrated in FIG. 1A as a flat key that canbe used with a mechanical delivery implant system (not pictured). Thetubular braid 110 can be formed into the predetermined shape by firstinverting the braid outwardly to separate the third segment 146 from thesecond segment 144 with a distal inversion 124. Then, the second segment144 can be shaped over a form to produce the substantially “S” shapedprofile illustrated in FIG. 1A. Next, the braid 110 can be invertedoutwardly again to separate the second segment 144 from the firstsegment 142 with a proximal inversion 122. Finally, the fourth segment152 can be shaped by expanding the fourth segment 152 radially. Thefourth segment 152 can be pressed distally into the first portion of thetubular braid 110. It can also be advantageous to minimize a neckopening 126 defined by the lower extension of the “S” shape of secondsegment 144 to maximize occlusion of an aneurysm neck when the implant100 is implanted.

The tubular braid 110 can include memory shape material that can be heatset to a predetermined shape, can be deformed for delivery through acatheter, and can self-expand to an implanted shape that is based on thepredetermined shape and confined by the anatomy of the aneurysm in whichit is implanted. When the tubular braid 110 is in the predeterminedshape as depicted in FIG. 1A, the fourth segment 152 can comprise adiameter D1 greater than or approximately equal to a maximum diameter D2of the first segment 142. Alternatively, when the tubular braid 110 isin the predetermined shape as depicted in FIG. 1A, the fourth segment152 can comprise a diameter D1 lesser than a maximum diameter D2 of thefirst segment 142. When the tubular braid 110 is in the predeterminedshape (FIG. 1A), the second segment 144 can form a sack, and at least aportion of the third segment 146 can positioned within the sack and atleast a portion of the fourth segment 152 can be positioned external tothe sack. As illustrated (FIG. 1B), when implanted, the fourth segment152 can be positioned external to the aneurysm sac, extending across theaneurysm neck 16. Preferably, the fourth segment 152 can apposevasculature walls surrounding the aneurysm neck 16 when implanted.Alternatively, the shaped fourth segment 152 can also be placed withinthe aneurysm sac. The detachment feature 150 can be implanted centrallyin the aneurysm neck 16. The detachment feature 150 can be positionedexternal to the sac 12.

The tubular braid 110 in the implanted shape (FIG. 1B) can be radiallyor vertically compressed or extended compared to the predeterminedshape. As illustrated in FIG. 1B, when in the implanted shape, the braid110 can have an outer layer 142 a corresponding to the first segment 142of the predetermined shape and positioned to contact an aneurysm wall 14of the aneurysm 10, a proximal inversion 122 a corresponding to theproximal inversion 122 of the predetermined shape and positioned to beplaced approximate a neck 16 of the aneurysm 10, and a sack 144 acorresponding to the second segment 144 of the predetermined shape andpositioned to appose a portion of the aneurysm wall 14 of the aneurysm10 and apposing the outer layer 142 a. A distal inversion 124 a cancorrespond to the distal inversion 124 of the predetermined shape, athird segment 146 a can correspond to the third segment 146 in thepredetermined shape. The braid 110 can also have a fourth segment 152 acorresponding to the fourth segment 152 of the predetermined shape andextending from the third segment 146 a radially outward from a centralaxis to cross the proximal inversion 122 a, fold, and converge at thepinched end 112. As described in FIG. 1A, the fourth segment 152 a canbe pressed distally into the first portion of the tubular braid 110.

By pressing the fourth segment 152 a distally into the first portion ofthe tubular braid 110, the first portion 142 a, 144 a, 146 a of thetubular braid 110 can be moved towards the distal portion of an aneurysmwall 15 to occlude a portion of the neck 16 of the aneurysm 10. Pushingthe fourth segment 152 a into the first portion of the braid 110 canhelp conform the implant 100 to the shape of the aneurysm 10 and resistcompaction. The fourth segment 152 a when expanded radially and pressedinto the first portion of the braid 110 also can provide additionalcoverage at the neck 16 of the aneurysm 10 to increase thrombosis andseal the aneurysm 10. When the fourth segment 152 a is pressed into thefirst portion of the braid 110, three layers of braid are present at theneck of the aneurysm. The fourth segment 152 a can cover spatial gapsbetween the first portion of implanted tubular braid 110 and theaneurysm neck 16, and can potentially increase metal coverage, decreaseporosity of the implant 100, and increase stasis and blood flowdiversion at the neck 16 of the aneurysm 10 to promote the sealing andthrombosis of the aneurysm 10. The fourth segment 152 a can be shaped toocclude the majority of an aneurysm neck 16 when the device 100 isimplanted. The fourth segment 152 a can be shaped to completely occludean aneurysm neck 16 when the device 100 is implanted.

When the tubular braid 110 is in the implanted shape (FIG. 1B), thefourth segment 152 a can comprise a diameter D1 greater than orapproximately equal to a maximum diameter D2 of the first segment 142 a.Alternatively, when the tubular braid 110 is in the implanted shape(FIG. 1B), the fourth segment 152 a can comprise a diameter D1 lesserthan a maximum diameter D2 of the first segment 142 a. When the tubularbraid 110 is in the implanted shape (FIG. 1B), the second segment 144 acan form a sack, and at least a portion of the third segment 146 a canbe positioned within the sack and at least a portion of the fourthsegment 152 a can be positioned external to the sack. The shaped fourthsegment 152 a can also be placed within the aneurysm sac 12 with onlythe detachment point 150 external to the sac 12.

FIGS. 2A through 2I are illustrations of an example implant 100 having abraid 110 expanding to an implanted shape that is based on apredetermined shape and the anatomy of the aneurysm and nearby bloodvessel as the braid 110 exits a microcatheter 600. The implant 100 has apredetermined shape similar to the shape illustrated in FIG. 1A. Asillustrated in FIG. 2A, the braid 110 can be shaped to a delivery shapethat is extended to a single layer of tubular braid having a compressedcircumference/diameter sized to be delivered through the microcatheter600 and a length L. As will be appreciated and understood by a person ofordinary skill in the art, the length L of a specific braid 110 can betailored based on the size and shape of the aneurysm being treated. Thelength L can be approximately 1 inch in length.

During delivery through the microcatheter 600, the detachment feature150 can be attached to a delivery system at a proximal end of theimplant 100, the pinched end 112 can be positioned near the proximal endof the implant 100, and the open end 114 can define the distal end ofthe implant 100. Collapsing the braid 110 to a single layer tube canresult in a braid 110 that has a sufficiently small diameter and asufficiently short length L to mitigate effects of friction force on thebraid 110 when it is delivered through the microcatheter, allowing thebraid 110 to be delivered unsheathed in some applications

As illustrated in FIG. 2B, the implant 100 can be delivered to ananeurysm 10 through the microcatheter 600. The open end 114 can bepositioned to exit the microcatheter 600 before any other portion of thebraid 110 exits the microcatheter. The open end 114 can expand withinthe aneurysm sac 12 as it exits the microcatheter 600. The illustratedaneurysm 10 is positioned at a bifurcation including a stem blood vessel700 and two branch vessels 702, and the microcatheter 600 is illustratedbeing delivered through the stem blood vessel 700. It is contemplatedthat the implant could be delivered to an aneurysm on a sidewall of ablood vessel through a curved microcatheter, and such a procedure isintended to be embraced by the scope of the present disclosure. Asillustrated in FIG. 2C, the distal portion of the braid 110 can continueto expand radially within the aneurysm sac 12 as it exits themicrocatheter 600. As the braid 110 is further pushed distally from themicrocatheter 600, the braid 110 can appose the aneurysm wall 14 andconform approximate the aneurysm neck 16. The aneurysm 10 being treatedcan have a diameter that is less than the outer diameter of the tubularbraid 110 in the predetermined shape so that the braid 110 tends toexpand outwardly, providing a force against the aneurysm wall 14 andsealing approximate the perimeter of the aneurysm neck 16.

As illustrated in FIG. 2D, the braid 110 can form the proximal inversion122 a defining the first segment 142 a as the braid 110 is furtherpushed out of the microcatheter 600. The proximal inversion 122 a can bepositioned approximate the aneurysm neck 16. The distal inversion 124 adefining the second segment 144 a can also begin to form as the braid110 is pushed out of the microcatheter 600. As illustrated in FIGS. 2Ethrough 2F, the “S” shape of the second segment 144 a can begin to formas the braid 110 is further pushed from the microcatheter 600.

As illustrated in FIG. 2G, once the first portion of the braid 110,which can comprise the first segment 142 a, second segment 144 a, andthird segment 146 a, is in place within the aneurysm sac 12, the fourthsegment 152 a can radially expand outside the aneurysm 10 as the distalportion of the braid 110 continues to exit the microcatheter 600.

As illustrated in FIG. 2H, the fourth segment 152 a can then becompressed distally as it continues to radially expand, compressing thefourth segment 152 a up into the first portion of the braid 110.

Finally, as illustrated in FIG. 2I, the fourth segment 152 a can becompressed distally into the first portion of the braid 110, at leastpartially occluding the neck 16 of the aneurysm 10 and the neck opening126. The pinched end 112 and/or the detachment point 150 can remainexternal to the aneurysm sac once the fourth segment 152 a has reachedits final expanded and compressed state. The fourth segment 152 a whencompressed can be compressed to a minimal thickness as to not become anobstruction to the surrounding blood vessels.

Before the implant 100 is released from the delivery system, the implant100 can be partially or fully retracted into the microcatheter 600 andrepositioned.

FIG. 3A is a flow diagram for a method 300 for forming an occlusivedevice to treat an aneurysm 10. Step 310 includes selecting an implantcomprising a tubular braid, an open end, and a pinched end. Step 320includes shaping the tubular braid to a predetermined shape, such as theone illustrated in FIG. 1A. As illustrated in FIG. 3B, step 320 canfurther comprise additional steps. Step 322 includes inverting thetubular braid to form a distal inversion. Step 324 inverts the tubularbraid to form a proximal inversion by moving the open end over at leasta portion of the braid. Step 326 includes shaping a first segment of thetubular braid extending between the open end and the proximal inversion.Step 328 shapes a second segment of the tubular braid extending betweenthe proximal inversion and the distal inversion. Step 330 includespositioning the open end to encircle the second segment. Step 332 shapesa third segment extending from the distal inversion to the proximalinversion. Step 334 includes positioning the second segment to surroundthe third segment. Step 336 shapes a fourth segment of the tubular braidextending from the third segment radially outward from a central axis tocross the proximal inversion, fold inwardly toward the central axis, andconverge at the pinched end. Step 338 includes positioning the fourthsegment approximate a neck of an aneurysm.

In method 300, step 320 of shaping the tubular braid to thepredetermined shape can further include shaping the fourth segment tocomprise a diameter greater than or approximately equal to a maximumdiameter of the first segment. In method 300, the step 320 of shapingthe tubular braid to the predetermined shape can further include shapingthe fourth segment to a diameter lesser than a maximum diameter of thefirst segment. The method 300 can further include shaping the tubularbraided implant to a delivery shape sized to traverse a lumen of amicrocatheter.

FIG. 4A is a flow diagram for a method 400 for a method for treating ananeurysm 10. Step 410 positions a first portion of a tubular braidedimplant, the tubular braided implant comprising a tubular braid, an openend, and a pinched end, within a sac of the aneurysm such that the firstportion circumferentially apposes walls within the sac. The firstportion can include one or more inversions. Step 420 includes expandinga second portion of the tubular braided implant radially to occlude amajority of a neck of the aneurysm. Step 430 presses the second portiondistally into the first portion. Pressing the second portion distallyinto the first portion can create three layers of braid at the neck ofthe aneurysm. The second portion can cover any spatial gaps between thefirst portion and the aneurysm neck, and can potentially increase metalcoverage, decrease porosity of the implant, and increase stasis andblood flow diversion at the neck of the aneurysm to promote the sealingand healing of the aneurysm. Step 440 includes moving the first portionof the tubular braided implant toward a distal portion of the aneurysmwall as a result of pressing the second portion distally into the firstportion.

As illustrated in FIG. 4B, step 420 can further include step 422, whichincludes positioning a fold in the second segment to define asubstantially circular perimeter of the second portion. Step 420 canadditionally, or alternatively include step 424, which includescompressing the second portion along a central axis of the tubularbraided implant such that the second portion comprises a substantiallycircular shape having an area and the second portion comprises twolayers of braid over a majority of the area of the substantiallycircular shape.

Step 410 can further include shaping the tubular braided implant to forma columnar post encircling a central axis of the tubular braided implantand extending a majority of a height of the first portion. Step 410 canfurther include positioning a proximal inversion in the first portion ofthe tubular braided implant approximate the neck of an aneurysm andpositioning a distal inversion in the first portion of the tubularbraided implant approximate the distal portion of the aneurysm wall.Step 410 can further include positioning the open end of the tubularbraided implant to circumferentially appose the aneurysm wall, shaping afirst segment of the tubular braid extending between the open end andthe proximal inversion to appose an at least a portion of a wall of theaneurysm within the aneurysm's sac, and shaping a second segment of thetubular braid such that the first segment provides an outwardly radialforce in a plane defining a boundary between the aneurysm and bloodvessel branches, the force sufficient to appose the first segment towalls of the aneurysm.

Step 430 can further include pressing the second portion of the tubularbraided implant against the proximal inversion in the first portion ofthe tubular braided implant. Step 440 can further include moving thedistal inversion in the first portion of the tubular braided implanttoward the distal portion of the aneurysm wall.

The method 400 can further include shaping the tubular braided implantto form a columnar post encircling a central axis of the tubular braidedimplant and extending a majority of a height of the first portion. Themethod 400 can further include retracting the tubular braid until adesired position is achieved relative to the aneurysm. The method 400can further comprise shaping the tubular braided implant to a deliveryshape sized to traverse a lumen of a microcatheter.

As used herein, the terms “about” or “approximately” for any numericalvalues or ranges indicate a suitable dimensional tolerance that allowsthe part or collection of components to function for its intendedpurpose as described herein.

The descriptions contained herein are examples of embodiments of theinvention and are not intended in any way to limit the scope of theinvention. The invention contemplates many variations and modificationsof the implant, including: alternative delivery methods, alternativebraid materials, alternative means for achieving a desiredstiffness/flexibility of braid material, additional structures affixedto the implant (e.g. to aid in anchoring the implant, blood flowdiversion, embolism formation, etc.), alternative predetermined braidshapes (e.g. one inversion, three inversions, four inversions, five ormore inversions, non-radially symmetric shapes, alternative segmentshapes, etc.), alternative implanted shapes, etc. The inventioncontemplates many variations and modifications to constructing theimplant to include combinations of the aforementioned variations andmodifications of the implant. The invention contemplates many variationsand modifications of implanting the implant to accommodate combinationsof the aforementioned variations and modifications of the implant.Modifications apparent to one of ordinary skill in the art following theteachings of this disclosure are intended to be within the scope of theclaims which follow.

What is claimed is:
 1. An implant comprising: a tubular braid comprisingan open end and a pinched end, the tubular braid further comprising apredetermined shape in which the tubular braid comprises: a firstsegment extending from the open end to a proximal inversion, a secondsegment encircled by the open end and extending from the proximalinversion to a distal inversion, a third segment surrounded by thesecond segment and extending from the distal inversion to the proximalinversion, and a fourth segment partially encircled by the proximalinversion and extending from the third segment radially outward from acentral axis to cross the proximal inversion, fold, and converge at thepinched end.
 2. The implant of claim 1, wherein, when the tubular braidis in the predetermined shape, the fourth segment comprises a diametergreater than or approximately equal to a maximum diameter of the firstsegment.
 3. The implant of claim 1, wherein, when the tubular braid isin the predetermined shape, the fourth segment comprises a diameterlesser than a maximum diameter of the first segment.
 4. The implant ofclaim 1, wherein, when the tubular braid is implanted in an aneurysm,the fourth segment occludes at least a portion of an aneurysm neck. 5.The implant of claim 1, wherein, when the tubular braid is in thepredetermined shape, the second segment forms a sack, at least a portionof the third segment is positioned within the sack, and at least aportion of the fourth segment is positioned external to the sack.
 6. Theimplant of claim 1, the tubular braid further comprising an implantedshape constrained by an aneurysm, in which the tubular braid comprises:an outer layer corresponding to the first segment of the predeterminedshape and positioned to contact an aneurysm wall of the aneurysm, aproximal inversion corresponding to the proximal inversion of thepredetermined shape and positioned to be placed approximate an aneurysmneck of the aneurysm, and a sack corresponding to the second segment ofthe predetermined shape and positioned to appose a portion of theaneurysm wall of the aneurysm and apposing the outer layer.
 7. Theimplant of claim 6, wherein, when the tubular braid is in the implantedshape, the fourth segment comprises a diameter greater than orapproximately equal to a maximum diameter of the first segment.
 8. Theimplant of claim 6, wherein, when the tubular braid is in the implantedshape, the fourth segment comprises a diameter lesser than a maximumdiameter of the first segment.
 9. The implant of claim 6, wherein, whenthe tubular braid is in the implanted shape, the fourth segment occludesat least a portion of an aneurysm neck.